So, I feel like this idea might have potential if you expanded a little more on it instead of just leaving it as a weird sort of thing that infected people and made them act like roman legionnaires. It isn’t executed particularly well, however. A few issues I noticed:

The use of “veteran” is a little off in the second paragraph of the description. First off, is it even required to be a veteran? It seems like, from the first paragraph, people actively in a military force could be affected by this. Second, I think it would seem more professional if it simply started off with “the person encountering SCP-XXXX, hereby referred to as SCP-XXXX-1,” and immediately designating it with a number instead of using “veteran” several times before designation.

How does one siege a 25 meter area? It seems like you would be setting up barricades and shit around, like, a tiny cabin in the middle of nowhere. You might want to increase the size for a siege, or just get rid of the size restrictions for all 3 things in the list. I can’t imagine the legionnaires would be like “Woah! We can’t attack that, its 26 meters in radius! Troops, retreat!” Even “approximately 25 meters” seems odd. They would surely just attack what they wanted to attack, no more, no less.

Who sends an entire MTF squad to investigate some people running around with swords in Italy? It seems like it would be far more likely to send a few agents to investigate. It honestly just sounds like an overdramatic “all of the highly trained people specifically equipped to deal with anomalous stuff died because the anomaly is so powerful”.

You shouldn’t really have an entire addendum just be a single note, in my opinion. It just looks out of place. I would replace it with normal, clinical text detailing what happened.

The interview honestly doesn’t add very much to the article. It’s just pointing out how they think that the roman empire is still a thing, which has pretty much already been established.

As for the concept, like I said it might have potential, but it isn’t all that interesting right now. You might want to consider adding some implication as to why the standard does what it does.1. You could also try and go down a more historical route, and write about how it affected the roman empire during its time, that sort of thing. It depends on exactly what you’re trying to do with this concept, which isn’t all that clear right now.

Hope this helped. Good luck!

Footnotes

1. Other than just some vague dialogue about a emperor, exactly which is redacted for no apparent reason.

Well sure, but correct me if I'm wrong, I don't think that is the actual definition of veteran, veteran is only for people who have served in the past but is not serving right now. You should use something like "officer" or "military personnel" simply because its more accurate to the definition of what you are trying to say.